http://www.e-codices.ch/it/bke/0065/52r
Engelberg, Stiftsbibliothek, Cod. 65, f. 52r – Tractatus sancti Ambrosii episcopi de officiis (http://www.e-codices.chit/bke/0065/52r)
Engelberg, Stiftsbibliothek, Cod. 65, f. 52r – Tractatus sancti Ambrosii episcopi de officiis (https://www.e-codices.ch/it/list/one/bke/0065)